Replace rust-tools with rustaceanvim (#166)

* Replace rust-tools with rustaceanvim

`rust-tools` is archived. The Astrocommunity Rust language pack has also moved to `rustaceanvim`.

* fix(rust): update rustaceanvim docs to use AstroLSP settings

---------

Co-authored-by: Micah Halter <[email protected]>

Author: jatinderjit

src/content/docs/recipes/advanced_lsp.mdx

@@ -566,7 +566,7 @@ return {
 }
 ```
 
-### Rust ([rust-tools.nvim](https://github.com/simrat39/rust-tools.nvim))
+### Rust ([rustaceanvim](https://github.com/mrcjkb/rustaceanvim))
 
 :::tip
 
@@ -581,19 +581,40 @@ return {
 
 :::
 
-```lua title="lua/plugins/rust-tools.lua"
+```lua title="lua/plugins/rustaceanvim.lua"
 return {
-  { "simrat39/rust-tools.nvim", lazy = true }, -- add lsp plugin
+  {
+    'mrcjkb/rustaceanvim', -- add lsp plugin
+    version = '^5',
+    lazy = false, -- This plugin is already lazy
+    opts = function(_, opts)
+      local astrolsp_avail, astrolsp = pcall(require, "astrolsp")
+      local astrolsp_opts = (astrolsp_avail and astrolsp.lsp_opts "rust_analyzer") or {}
+      local server = {
+        ---@type table | (fun(project_root:string|nil, default_settings: table|nil):table) -- The rust-analyzer settings or a function that creates them.
+        settings = function(project_root, default_settings)
+          local astrolsp_settings = astrolsp_opts.settings or {}
+
+          local merge_table = require("astrocore").extend_tbl(default_settings or {}, astrolsp_settings)
+          local ra = require "rustaceanvim.config.server"
+          -- load_rust_analyzer_settings merges any found settings with the passed in default settings table and then returns that table
+          return ra.load_rust_analyzer_settings(project_root, {
+            settings_file_pattern = "rust-analyzer.json",
+            default_settings = merge_table,
+          })
+        end,
+      }
+      return { server = require("astrocore").extend_tbl(astrolsp_opts, server) }
+    end,
+    -- configure `rustaceanvim` by setting the `vim.g.rustaceanvim` variable
+    config = function(_, opts) vim.g.rustaceanvim = require("astrocore").extend_tbl(opts, vim.g.rustaceanvim) end,
+
+  },
   {
     "AstroNvim/astrolsp",
     ---@type AstroLSPOpts
     opts = {
-      setup_handlers = {
-        -- add custom handler
-        rust_analyzer = function(_, opts)
-          require("rust-tools").setup({ server = opts })
-        end,
-      },
+      handlers = { rust_analyzer = false }, -- Let rustaceanvim setup `rust_analyzer`
     },
   },
   {